const state = faste()
 .withPhases(['red', 'yellow', 'green'])
 .withMessages(['tick','next'])

 .on('tick',['green'], ({transit}) => transit('yellow'))
 .on('tick',['yellow'], ({transit}) => transit('red'))
 .on('tick',['red'], ({transit}) => transit('green'))
  // just rethrow next as tick
 .on('next',[], ({trigger}) => trigger('tick'))

 .on('@enter',['green'], ({setState, attrs, trigger}) => setState({
    // timer "ticks" by "tick", as it should
    interval: setInterval(() => trigger('next'), attrs.duration)
 }))
 .on('@leave',['red'], ({state}) => clearInterval(state.interval))

state
  .create()
  .attrs({duration: 1000})
  .start('green');